Spring tire wheel assembly with bump stop

ABSTRACT

A wheel assembly that includes an outer rim assembly with a first outer rim portion, a second outer rim portion, and a plurality of outer cross members extending between the first and second outer rim portions, a tire assembly secured to the outer rim assembly, and at least a first bump stop assembly. The tire assembly includes an outer main body portion that includes first and second outer side wall portions and an outer contact portion extending transversely between the first and second outer side wall portions. The first bump stop assembly includes a first inner rim portion, a second inner rim portion and an inner main body portion. The inner main body portion includes first and second inner side wall portions and an inner contact portion extending transversely between the first and second inner side wall portions. The inner contact portion is coupled to the outer contact portion.

CROSS-REFERENCE TO RELATED APPLICATIONS

This application claims the benefit of U.S. Provisional Application No.63/305,109, filed on Jan. 31, 2022, the entirety of which isincorporated by reference herein.

FIELD OF THE INVENTION

The present invention relates to a spring tire that may include shapememory alloys (“SMAs”), and more particularly to a spring tire that mayinclude shape memory alloys, a bump stop and integrated tread lugs.

BACKGROUND OF THE INVENTION

Non-pneumatic tire designs that includes helical springs as thestructural elements are known (known as spring tires). These tires wereinvented to provide improved load carrying capacity and long life ascompared to the original “moon tire” used for lunar exploration.However, these prior art tires are deficient relative to the presentinvention in that they include limited load carrying capacity, theability to “unwind” and come part, are prone to permanent damage whendeformed (made from spring steel), and are very heavy. Later, steelsprings were replaced with shape memory alloy springs, for improvedperformance.

The background description disclosed anywhere in this patent applicationincludes information that may be useful in understanding the presentinvention. It is not an admission that any of the information providedherein is prior art or relevant to the presently claimed invention, orthat any publication specifically or implicitly referenced is prior art.

SUMMARY OF THE PREFERRED EMBODIMENTS

In accordance with a first embodiment of the present invention there isprovided a wheel assembly that includes an outer rim assembly having afirst outer rim portion, a second outer rim portion and a plurality ofouter cross members extending between the first outer rim portion andthe second outer rim portion, a tire assembly that includes an outermain body portion, and at least a first bump stop assembly that includesa first inner rim portion, a second inner rim portion and an inner mainbody portion. The outer main body portion includes a plurality of outershape memory elements having first and second opposite ends. The firstend of each outer shape memory element is secured or connected to thefirst outer rim portion and the second end of each outer shape memoryelement is secured or connected to the second outer rim portion. Theouter main body portion includes a first outer side wall portion, asecond outer side wall portion and an outer contact portion extendingtransversely between the first and second outer side wall portions. Theinner main body portion includes a plurality of inner shape memoryelements having first and second opposite ends. The first end of eachinner shape memory element is secured or connected to the first innerrim portion and the second end of each inner shape memory element issecured or connected to the second inner rim portion. The inner mainbody portion includes a first inner side wall portion, a second innerside wall portion and an inner contact portion extending transverselybetween the first and second inner side wall portions. The inner contactportion is coupled to the outer contact portion.

In a preferred embodiment, the wheel assembly includes a tread portionhaving a plurality of tread shape memory elements. The tread portioncouples the inner contact portion to the outer contact portion.Preferably, the plurality of tread shape memory elements comprises atleast first and second tread shape memory elements, the plurality ofouter shape memory elements comprises at least first and second outershape memory elements, and the plurality of inner shape memory elementscomprises at least first and second inner shape memory elements. Thefirst tread shape memory element may couple the first outer shape memoryelement to the first inner shape memory element. In a preferredembodiment, the first tread shape memory element wraps, extends or coilsaround the first outer shape memory element and the first inner shapememory element, thereby coupling the first outer shape memory element tothe first inner shape memory element.

In a preferred embodiment, the first tread shape memory element includesa plurality of coils and defines a spring or coil interior and the firstouter shape memory element and the first inner shape memory elementextend through the spring interior, thereby coupling the first outershape memory element to the first inner shape memory element. The secondtread shape memory element may include a plurality of coils and at leastone of the plurality of coils of the first tread shape memory elementmay be connected to at least one of the plurality of coils of the secondtread shape memory element.

The plurality of outer cross members may define a stop surface and thefirst and second inner rim portions may define an inner contact surface.A deflection distance may be defined between the inner contact surfaceand the stop surface and when the outer main body portion is deflected apredetermined distance the inner contact surface contacts the stopsurface. The plurality of outer shape memory elements may include afirst set of lug shape memory elements and a second set of non-lug shapememory elements where the lug shape memory elements have a greaterstiffness than the non-lug shape memory elements.

In a preferred embodiment of the invention, the wheel assembly mayinclude a second bump stop assembly that includes a second inner contactportion that is coupled to the outer contact portion. The plurality ofouter shape memory elements, tread shape memory elements and pluralityof inner shape memory elements may be made of a shape memory alloy.

In accordance with another aspect of the present invention there isprovided a wheel assembly that includes an outer rim assembly thatincludes a first outer rim portion, a second outer rim portion, and aplurality of outer cross members extending between the first outer rimportion and the second outer rim portion, a tire assembly secured to theouter rim assembly, and at least a first bump stop assembly. The tireassembly includes an outer main body portion that includes a first outerside wall portion, a second outer side wall portion and an outer contactportion extending transversely between the first and second outer sidewall portions. The first bump stop assembly includes a first inner rimportion, a second inner rim portion and an inner main body portion. Theinner main body portion includes a first inner side wall portion, asecond inner side wall portion and an inner contact portion extendingtransversely between the first and second inner side wall portions. Theinner contact portion is coupled to the outer contact portion. The tireassembly defines a tire assembly outer diameter and the inner contactportion may be coupled to the outer contact portion about the tireassembly outer diameter. The present invention is directed to a wheelassembly that includes a tire assembly that may be both top and bottomloading, provides a flexible inner bump stop for heavy loads, a flat (orother shaped wire tread for increased traction, and variable stiffnessradials or side walls for climbing capability. The current inventionenables superior load carrying, flotation, climbing and tractioncapabilities for a spring tire, when compared to the prior art.

In a preferred embodiment, the inventive tire assembly may include aninner bump stop assembly. Shorter radial elements may provide highload-carrying capability at the point of contact. The side walls of thebump stop assembly are preferably shaped to act as a column or providecolumnar strength. During use, the bump stop is engaged under normalconditions, instead of acting only as a protection against excessivedeflection of the tire (where the outer surface of the bump stop isspaced from the outer surface of the tire). Due to its relatively smallsize, the tire assembly is also lightweight. The inner bump stopassembly may aid with increased load carrying capacity, improvedfootprint and evenly distributed ground pressure. The bump stop assemblyis designed to optimize the tire footprint and better distribute groundpressure (as a result of the connection of the contact portion of thebump stop assembly to the contact portion of the outer main bodyportion). Furthermore, when the tire assembly encounters a predeterminedamount of deflection, the bump stop assembly is configured to contactthe cross members or spacers or other portion of the outer rim assemblyto prevent any further deflection. The bump stop on previous lunarroving vehicle (LRV) tires only engaged when the tire was overlydeflected, thus adding mass to the tire which is rarely used.

In a preferred embodiment, the tire may include flat wire springs forthe tread element. The flat tread springs provide for improved tractionand flotation. As compared to round wire springs, the spring elementsare more resistant to unscrewing. However, in another embodiment, thetread element can include non-flat or round wire springs. Tread designbecomes independent of load carrying capacity so flotation and tractioncan be tailored to the environment. Adjacent tread shape memory elementsor springs may be interwoven with one another as well as with thecontact portions of the tire assembly and the bump stop assembly.

In a preferred embodiment, at least some of the various wires/springs ofthe different elements or components of the tire assembly are interwovenwith one another. For example, the wire elements of the bump stop orbump stop assembly (e.g., the contact portion) may be interwoven with orotherwise connected to the contact portion of the tire assembly orradial elements. This feature, combined with the use of a spoked wheelto distribute load to the entire wheel (e.g., around the contact surfaceof the wheel in the case of the interwoven or connected contactportions), as opposed to a top-loading or bottom-loading tire, isinnovative. Typically, wheels often are only bottom loading where allfootprint forces are transferred to the rim through the contact patch(the area of the tire contacting the ground). However, the presentinvention allows the load to be transferred around the outer diameter(OD) of the wheel assembly as a result of the circular bump stopassembly being secured or connected to the tire assembly. In otherwords, the bump stop springs or inner shape memory elements, radialsprings or outer shape memory elements and the tread springs or treadshape memory elements are woven or connected together so that load istransferred from the footprint to the entire OD of the wheel assembly,which may increase load carrying capacity of a vehicle equipped with oneor more of the wheel assemblies without additional weight.

In a preferred embodiment, the tire assembly may include the alternatinguse of stiffer or softer springs in the tread element, in order toprovide uneven deflection, which is useful for climbing. The tread lugsinclude radial elements (e.g., wires) of variable stiffness or differentstiffness than the other wires in the main body portion. To aid inclimbing ability, the tire's radial elements are designed to havevariable stiffness. By alternating the deflection of different areas ofthe tire, tread lugs or lug sections are formed when sufficient pressureis applied. To aid in tire climbing, soft springs deflect more than thestiffer springs, thus the stiffer springs act like tread lug. The lugsections may also provide help with traction in sand and other granularenvironments.

The tread shape memory elements, outer shape memory elements and/orinner shape memory elements (any of the shape memory elements, wire,springs, etc.) may have any cross-sectional shape, e.g., flat, round,rectangular, etc. It will be appreciated by those of ordinary skill inthe art that the load carrying capacity of the inner bump stop assembly(and the springs or SMA wires or elements thereof) is highest at thecrown of the tire assembly, offsetting the lowest capacity area of theouter springs, where it is inner woven with the outer contact portion ofthe main body portion, and the springs, wires or elements of the treadportion. In a preferred embodiment, the various wires, springs orelements of the present invention are made of a shape memory alloy andare configured to retain or return to their original shape after a load,force or the like is applied thereto. It will be appreciated that theterm shape memory alloy is not intended to be limiting. Furthermore, theuse of the term “shape memory” is not intended to limit the component tohaving to made from or comprise a shape memory alloy. Any elements thatinclude the phrase “shape memory”, including, but not limited to outershape memory element, inner shape memory element and tread shape memoryelement, are not limited to comprising a shape memory element, but areconfigured to retain or return to their original or initial shape afterhaving been deformed. This can include a spring or spring material.

In a preferred embodiment, the wheel assembly is also both top andbottom loading. In use, the tire portion is bottom loading where thefootprint forces are transferred to the rim assembly through the radialwires in the contact path. However, the tire assembly is also toploading where the bump stop assembly springs or inner shape memoryelements, main body portion springs or outer shape memory elements andthe tread portion or tread shape memory elements are woven together sothat load is transferred from the footprint to the entire outer diameterof the wheel assembly, thereby increasing load carrying capacity. In apreferred embodiment, the bump stop assembly is only connected to thetire assembly or the outer shape memory elements via the connectionbetween the inner and outer contact portions. Otherwise, the bump stopassembly is free to move within the tire interior. The top loaded tireis similar to a regular bicycle rim where if a load is applied at theaxle, the assembly can carry the load with a single spoke and the loadis distributed around the entire rim.

Tire characteristics, ability and other considerations, such astraction, flotation, weight capacity, etc. can be changed or fine-tunedbased on the number or density of the outer shape memory elements, innershape memory elements and/or tread shape memory elements, the shape,stiffness, spring constant or other characteristics of the various shapememory elements, among other things. The tread shape may be adjusted viathe number of tread springs.

In a preferred embodiment, the wheel assembly also provides damping. Forexample, in an exemplary embodiment, the present invention may providenaturally occurring damping with 785 tread springs (around thecircumference of the tire assembly), 51 pitches per spring, whichprovides 40,000 frictional contact points for natural damping. In anexemplary embodiment, the tread springs or tread shape memory elementsmay comprise 0.040″ diameter, spring steel and are 12.75″ long, 0.23″ ODand 0.216″ pitch with open ends. In an exemplary embodiment, the radialsprings or outer shape memory elements may comprise 0.050″ filamentdiameter 8″ long, piano wire.

BRIEF DESCRIPTION OF THE DRAWINGS

FIG. 1 is a side elevational view of a wheel assembly in accordance witha preferred embodiment of the present invention;

FIG. 2 is a perspective view of the wheel assembly of FIG. 1 ;

FIG. 3 is a cross-sectional perspective view of a portion of the wheelassembly of FIG. 1 ;

FIG. 4 is another cross-sectional perspective view of a portion of thewheel assembly of FIG. 1 ;

FIG. 5 is another cross-sectional perspective view of a portion of thewheel assembly of FIG. 1 ;

FIG. 6 is a perspective view of a wheel assembly with first and secondbump stop assemblies in accordance with a preferred embodiment of thepresent invention;

FIG. 7 is a cross-sectional elevational view of a portion of the wheelassembly of FIG. 6 ; and

FIG. 8 shows a portion of a tire assembly with adjacent tread springsinterwoven with one another.

Like numerals refer to like parts throughout the several views of thedrawings.

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS

The following description and drawings are illustrative and are not tobe construed as limiting. Numerous specific details are described toprovide a thorough understanding of the disclosure. However, in certaininstances, well-known or conventional details are not described in orderto avoid obscuring the description. References to one or an embodimentin the present disclosure can be, but not necessarily are references tothe same embodiment; and, such references mean at least one of theembodiments. If a component is not shown in a drawing then this providessupport for a negative limitation in the claims stating that thatcomponent is “not” present. However, the above statement is not limitingand in another embodiment, the missing component can be included in aclaimed embodiment.

Reference in this specification to “one embodiment,” “an embodiment,” “apreferred embodiment” or any other phrase mentioning the word“embodiment” means that a particular feature, structure, orcharacteristic described in connection with the embodiment is includedin at least one embodiment of the-disclosure and also means that anyparticular feature, structure, or characteristic described in connectionwith one embodiment can be included in any embodiment or can be omittedor excluded from any embodiment. The appearances of the phrase “in oneembodiment” in various places in the specification are not necessarilyall referring to the same embodiment, nor are separate or alternativeembodiments mutually exclusive of other embodiments. Moreover, variousfeatures are described which may be exhibited by some embodiments andnot by others and may be omitted from any embodiment. Furthermore, anyparticular feature, structure, or characteristic described herein may beoptional. Similarly, various requirements are described which may berequirements for some embodiments but not other embodiments. Whereappropriate any of the features discussed herein in relation to oneaspect or embodiment of the invention may be applied to another aspector embodiment of the invention. Similarly, where appropriate any of thefeatures discussed herein in relation to one aspect or embodiment of theinvention may be optional with respect to and/or omitted from thataspect or embodiment of the invention or any other aspect or embodimentof the invention discussed or disclosed herein.

The terms used in this specification generally have their ordinarymeanings in the art, within the context of the disclosure, and in thespecific context where each term is used. Certain terms that are used todescribe the disclosure are discussed below, or elsewhere in thespecification, to provide additional guidance to the practitionerregarding the description of the disclosure. For convenience, certainterms may be highlighted, for example using italics and/or quotationmarks: The use of highlighting has no influence on the scope and meaningof a term; the scope and meaning of a term is the same, in the samecontext, whether or not it is highlighted.

It will be appreciated that the same thing can be said in more than oneway. Consequently, alternative language and synonyms may be used for anyone or more of the terms discussed herein. No special significance is tobe placed upon whether or not a term is elaborated or discussed herein.Synonyms for certain terms are provided. A recital of one or moresynonyms does not exclude the use of other synonyms. The use of examplesanywhere in this specification including examples of any terms discussedherein is illustrative only, and is not intended to further limit thescope and meaning of the disclosure or of any exemplified term.Likewise, the disclosure is not limited to various embodiments given inthis specification.

Without intent to further limit the scope of the disclosure, examples ofinstruments, apparatus, methods and their related results according tothe embodiments of the present disclosure are given below. Note thattitles or subtitles may be used in the examples for convenience of areader, which in no way should limit the scope of the disclosure. Unlessotherwise defined, all technical and scientific terms used herein havethe same meaning as commonly understood by one of ordinary skill in theart to which this disclosure pertains. In the case of conflict, thepresent document, including definitions, will control.

It will be appreciated that terms such as “front,” “back,” “top,”“bottom,” “side,” “short,” “long,” “up,” “down,” “aft,” “forward” and“below” used herein are merely for ease of description and refer to theorientation of the components as shown in the figures. It should beunderstood that any orientation of the components described herein iswithin the scope of the present invention.

Described herein and shown in FIGS. 1-5 is a wheel assembly 10 inaccordance with a preferred embodiment of the present invention thatincludes an outer rim assembly 12, a tire assembly 13, at least one bumpstop assembly 18 and a tread portion 16. In a preferred embodiment, theouter rim assembly 12 includes left and right or first and second outerrim portions 20, a plurality of spoke members 22 (that extend outwardlyfrom a central hub 23) and a plurality of outer cross members 24extending between the first outer rim portion 20 and the second outerrim portion 20. The spoke members 22 extend generally radially outwardlyand connect to one of the first and second outer rim portions 20. In apreferred embodiment, each spoke member 22 extends to and is secured toor with an end of one of the outer cross members 24. A fastener, such asthreaded fasteners 29 or the like, may be used to secure or attach theouter cross members 24 and/or the distal or outer ends of the spokemember 22 to the first and second outer rim portions 20 (see FIG. 3 ).Any arrangement of spokes or spoke members extending outwardly to a rimor outer rim portions 20 is within the scope of the present invention.Welding, gluing, adhering or other attachment method can be used toattach or secure the various components, such as the outer cross members24, first and second outer rim portions 20 and spoke member 22 to oneanother. Preferably, the bump stop assembly 18 extends around the entirecircumference of the wheel assembly and, in particular, around the innerdiameter of the tire assembly 13.

The tire assembly 13 includes an outer main body portion 14 and thetread portion 16. The tire assembly 13, including the outer main bodyportion 14 and the tread portion 16, are formed from or comprise a largenumber of shape memory elements, wires or springs that are interwovenwith one another. As a result, when showing the tire assembly 13 in thefigures the various shape memory elements can be difficult to see.Therefore, it will be appreciated that due to the large number of shapememory elements, portions of FIG. 2 are shown as a solid shape with justa portion of the plurality of wires making up the tire portion 13 shownin detail. It should be understood that, as shown in FIG. 1 , the entiretire assembly 13 comprises individual shape memory elements. Theportions shown as solid sections in FIG. 2 are only shown this way fordrawing simplicity.

As shown in FIGS. 3-4 , the outer main body portion 14 includes aplurality of outer shape memory elements 26 (e.g., a plurality of SMAsprings or wires) having first and second opposite ends 26 a. The firstend 26 a of each outer shape memory element 26 is connected to the firstouter rim portion 20 and the second end 26 a of each outer shape memoryelement is connected to the second outer rim portion 20. Preferably, theouter main body portion 14 includes first and second outer side wallportions 28 and an outer contact portion 30 extending transverselybetween the first and second outer side wall portions 28. As shown inFIG. 3 , the SMA wires or outer shape memory elements 26 extend radiallyoutwardly from the first outer rim portion 20 to form the first outerside wall portion 28, then curve or extend transversely to form theouter contact portion 30 and then extend radially inwardly to form thesecond outer side wall portion 28 and to the second outer rim portion20. In a preferred embodiment, each outer shape memory element 26includes connection portions 27 at the opposite ends thereof that eachextend through one more connection openings 31 (see FIG. 6 ) defined inthe first and second outer rim portions 20. In a preferred embodiment,the outer rim portions 20 each include two connection openings 31.However, the connection portions 27 can also extend through a singleconnection opening. Any method for connecting the opposite ends of theouter shape memory elements 26 to the first and second outer rimportions 20 is within the scope of the present invention. The connectionportions 27 may help protect the first and second outer rim portions 20.

The bump stop assembly 18 includes left and right or first and secondinner rim portions 32, a plurality of inner cross members 34 extendingbetween the first and second inner rim portions 32 and an inner mainbody portion 36. The inner main body portion 36 preferably includes aplurality of inner shape memory elements 38 (e.g., a plurality of SMAsprings or wires) having first and second opposite ends 38 a. The firstend 38 a of each inner shape memory element 38 is connected to the firstinner rim portion 32 and the second end 38 a of each inner shape memoryelement 38 is connected to the second inner rim portion 32. The innermain body portion 36 includes left and right or first and second innerside wall portions 40 and an inner contact portion 42 extendingtransversely between the first and second inner side wall portions 40.In a preferred embodiment, the outer main body portion 14 defines a tireinterior 25 and at least a portion of the bump stop assembly 18 isdisposed in the tire interior 25. As shown in FIG. 4 , the inner shapememory elements 38 extend radially outwardly from the first inner rimportion 32 to form the first inner side wall portion 40, then extendtransversely to form the inner contact portion 42 and then extendradially inwardly to the second inner rim portion 32. In a preferredembodiment, each inner shape memory element 38 includes connectionportions 39 at the opposite ends thereof that each extend through onemore connection openings 31 defined in the first and second inner rimportions 32. In a preferred embodiment, the inner rim portions 32 eachinclude two connection openings 31. Any method for connecting theopposite ends of the inner shape memory elements 38 to the first andsecond inner rim portions 32 is within the scope of the presentinvention.

In a preferred embodiment, the inner shape memory elements 38 of thebump stop assembly 18 are interwoven with, connected to or are otherwisesecured to or with the outer shape memory elements 26 of the outer mainbody portion 14. Preferably, the inner contact portion 42 is secured tothe outer contact portion 30. As a result, the bump stop assembly 18 isload carrying. In a preferred embodiment, the tread portion 16 includesa plurality of tread shape memory elements 44 (e.g., a plurality of SMAsprings or wires). Each of the tread shape memory elements 44 preferablyextend, wrap or coil around one or more of the outer shape memoryelements 26 (and the outer contact portion 30 thereof). As shown inFIGS. 4 and 5 , in a preferred embodiment, each of the tread shapememory elements 44 also extend, wrap or coil around at least a portionof one or more of the inner shape memory elements 38 (and the innercontact portion 42 thereof). Therefore, the tread shape memory elements44 secure the outer contact portion 30 to the inner contact portion 42.FIGS. 3 and 4 show each tread shape member element 44 coil or wraparound a single inner contact portion 42 and outer contact portion 30.FIG. 5 shows each tread shape member element 44 coil or wrap around twoinner contact portions 42 and two outer contact portions 30. Any weavingpattern is within the scope of the present invention provided the treadshape member elements 44 connect or secure the inner contact portions 42to the outer contact portions. In other words, the tread portion 16couples or secures together the inner shape memory elements to the outershape memory elements or the tread portion 16 couples or securestogether the inner contact portion and the outer contact portion.

The tread shape memory elements 44 of the tread portion 16 arepreferably interwoven with the inner shape memory elements 38 of theouter main body portion 14 (and specifically at least a portion of theouter contact portion 30 thereof) and the inner contact portion 42 ofthe bump stop assembly 18. The tread portion 16 springs being wrappedaround or interwoven with the bump stop assembly 18 springs, wires orelements helps keep the tread portion 16 centered.

As shown in FIGS. 1-3 , in a preferred embodiment, the wheel assembly 10includes a plurality of lug sections 46. The lug sections 46 are shownwith dashed lines in FIGS. 1-3 only to differentiate them from thenon-lug sections. The lug sections 46 are formed by or comprise one ormore (preferably a set of) outer shape memory elements 26 having adifferent stiffness than the surrounding or other outer shape memoryelements 26 of the outer main body portion 14. For example, FIG. 1 showsfive lug sections 46 around the circumference of the tire assembly 13 orouter main body portion 14. Each outer shape memory element 26 withinthe set of outer shape memory elements 26 in each lug section 46 has adifferent or higher stiffness than the outer shape memory elements 26that are not within the lug sections 46. The outer shape memory elements26 that are not within a lug section or set may be referred to herein asa regular or non-lug set or section. Therefore, the lug sections or setsand regular or non-lug sections or sets are preferably alternating. Thisessentially provides a first set of outer shape memory elementscomprising harder springs and a second set of outer shape memoryelements comprising softer springs. These lug sections 46 aid inclimbing ability. For example, if the lug sections 46 have a greaterstiffness than the remainder of the outer main body portion 14 (referredto herein as the non-lug sections—one of which is labeled as non-lugsection 47 in FIG. 1 ), then the non-lug sections will deflect more thanthe lug sections 46 when a hard object (e.g., a rock) is contacted bythe wheel assembly. Due to the higher stiffness of the lug section 46,the lug section 46 provides leverage against the object to help thewheel assembly climb over the object. In short, by alternating thedeflection of different areas or sections of the outer main body portion14 (different sets of outer shape memory elements), the lug sections 46provide a different shape when sufficient pressure is applied by anobject against the tire assembly. Lug sections can also be included inthe bump stop assembly.

FIGS. 6-8 show another preferred embodiment of the present inventionembodied in a wheel assembly 50 that includes two or first and secondbump stop assemblies 18. All description herein associated with wheelassembly 10 also applies to wheel assembly 50. The embodiments and thecomponents of each are interchangeable. In another embodiment, more thantwo bump stop assemblies can be included.

The SMA wires or outer shape memory elements 26 extend radiallyoutwardly from the first outer rim portion 20 to form the first outerside wall portion 28, then curve or extend transversely to form theouter contact portion 30 and then extend radially inwardly to form thesecond outer side wall portion 28 and to the second outer rim portion20. To accommodate the first and second bump stop assemblies 18, theouter contact portion 30 of wheel assembly 50 has a wider and/or flatterconfiguration than the outer contact portion 30 of wheel assembly 10. Ina preferred embodiment, each of the tread shape memory elements 44 ofthe tread portion 16 are preferably interwoven with the outer contactportion 30 and the inner contact portions 42 of the first and secondbump stop assemblies 18.

Wheel assembly 50 with two bump top assemblies may provide a wider tireto reduce ground pressure for better floatation in soft soils, reducedfilament diameter in bump stops, reducing stress in filament fordurability and longevity particularly at cryogenic temperatures,redundancy for safety, good traction in soft soils, and higher loadcarrying capacities.

The tread portion 16 and the tread shape memory elements 44 thereof mayextend only partially along the outer main body portion 14 (and theouter shape memory elements 26 thereof), as shown in FIGS. 1 and 2-5 orall the way from the first outer rim portion 20 to the second outer rimportion 20, as shown in FIGS. 6 and 7 .

For both wheel assembly 10 and wheel assembly 50, during use, the tireassembly 13 (the outer main body portion 14 and tread portion 16) maydeflect when coming into contact with or rolling over an object. As aresult, the bump stop assembly 18 will deflect or move radially inwardlytoward the center of the wheel assembly. In a preferred embodiment, thebump stop assembly 18 includes a maximum deflection position where thefirst and second inner rim portions 32 contact or are stopped by one ormore of the outer cross members 24. More specifically, the inner contactsurface 32 a of the first and second inner rim portions 32 contacts anouter surface 24 a of one or more of the outer cross members 24 (seeFIGS. 3 and 7 ). The outer surfaces 24 a of the outer cross members 24together combine to form a stop surface. The space or distance betweenthe first and second inner rim portions 32 and the outer cross members24 may be referred to herein as the deflection space or deflectiondistance and is labeled D1 in FIG. 7 . In another embodiment, theplurality of outer cross members (or inner cross members) can be acircular wall, like the transverse or bottom wall on a typical rim. Itshould be understood that such a transverse wall reads on a plurality ofcross members.

Adjacent tread shape memory elements or springs may be interwoven withone another as well as with the contact portions of the tire assemblyand the bump stop assembly. For example, see FIG. 8 , which shows eachtread shape memory element 44 in a coiled spring shape having aplurality of coils 44 a and defining a spring interior 44 b. One outershape memory element 26 and inner shape memory element 38 extend throughthe spring interior 44 b, thereby coupling the outer shape memoryelement 26 to the first inner shape memory element 38. Also, individualcoils 44 a of one tread shape memory element can be interwoven,interlocked or connected to individual coils of adjacent tread shapememory elements, as shown in FIG. 8 . This configuration providescircumferential stability and may help provide increased traction.Furthermore, it will be appreciated that the coil shape of the treadshape memory elements may help with traction.

Unless the context clearly requires otherwise, throughout thedescription and the claims, the words “comprise,” “comprising,” and thelike are to be construed in an inclusive sense, as opposed to anexclusive or exhaustive sense; that is to say, in the sense of“including, but not limited to.” As used herein, the terms “connected,”“coupled,” or any variant thereof, means any connection or coupling,either direct or indirect, between two or more elements; the coupling ofconnection between the elements can be physical, logical, or acombination thereof. Additionally, the words “herein,” “above,” “below,”and words of similar import, when used in this application, shall referto this application as a whole and not to any particular portions ofthis application. Where the context permits, words in the above DetailedDescription of the Preferred Embodiments using the singular or pluralnumber may also include the plural or singular number respectively. Theword “or” in reference to a list of two or more items, covers all of thefollowing interpretations of the word: any of the items in the list, allof the items in the list, and any combination of the items in the list.

The above-detailed description of embodiments of the disclosure is notintended to be exhaustive or to limit the teachings to the precise formdisclosed above. While specific embodiments of and examples for thedisclosure are described above for illustrative purposes, variousequivalent modifications are possible within the scope of thedisclosure, as those skilled in the relevant art will recognize.Further, any specific numbers noted herein are only examples:alternative implementations may employ differing values, measurements orranges.

Although the operations of any method(s) disclosed or described hereineither explicitly or implicitly are shown and described in a particularorder, the order of the operations of each method may be altered so thatcertain operations may be performed in an inverse order or so thatcertain operations may be performed, at least in part, concurrently withother operations. In another embodiment, instructions or sub-operationsof distinct operations may be implemented in an intermittent and/oralternating manner.

The teachings of the disclosure provided herein can be applied to othersystems, not necessarily the system described above. The elements andacts of the various embodiments described above can be combined toprovide further embodiments. Any measurements or dimensions described orused herein are merely exemplary and not a limitation on the presentinvention. Other measurements or dimensions are within the scope of theinvention.

Any patents and applications and other references noted above, includingany that may be listed in accompanying filing papers, are incorporatedherein by reference in their entirety. Aspects of the disclosure can bemodified, if necessary, to employ the systems, functions, and conceptsof the various references described above to provide yet furtherembodiments of the disclosure.

These and other changes can be made to the disclosure in light of theabove Detailed Description of the Preferred Embodiments. While the abovedescription describes certain embodiments of the disclosure, anddescribes the best mode contemplated, no matter how detailed the aboveappears in text, the teachings can be practiced in many ways. Details ofthe system may vary considerably in its implementation details, whilestill being encompassed by the subject matter disclosed herein. As notedabove, particular terminology used when describing certain features oraspects of the disclosure should not be taken to imply that theterminology is being redefined herein to be restricted to any specificcharacteristics, features or aspects of the disclosure with which thatterminology is associated. In general, the terms used in the followingclaims should not be construed to limit the disclosures to the specificembodiments disclosed in the specification unless the above DetailedDescription of the Preferred Embodiments section explicitly defines suchterms. Accordingly, the actual scope of the disclosure encompasses notonly the disclosed embodiments, but also all equivalent ways ofpracticing or implementing the disclosure under the claims.

While certain aspects of the disclosure are presented below in certainclaim forms, the inventors contemplate the various aspects of thedisclosure in any number of claim forms. For example, while only oneaspect of the disclosure is recited as a means-plus-function claim under35 U.S.C. § 112, ¶6, other aspects may likewise be embodied as ameans-plus-function claim, or in other forms, such as being embodied ina computer-readable medium. (Any claims intended to be treated under 35U.S.C. § 112, ¶6 will include the words “means for”). Accordingly, theapplicant reserves the right to add additional claims after filing theapplication to pursue such additional claim forms for other aspects ofthe disclosure.

Accordingly, although exemplary embodiments of the invention have beenshown and described, it is to be understood that all the terms usedherein are descriptive rather than limiting, and that many changes,modifications, and substitutions may be made by one having ordinaryskill in the art without departing from the spirit and scope of theinvention.

What is claimed is:
 1. A wheel assembly comprising: an outer rimassembly that includes a first outer rim portion, a second outer rimportion, and a plurality of outer cross members extending between thefirst outer rim portion and the second outer rim portion, a tireassembly that includes an outer main body portion, wherein the outermain body portion includes a plurality of outer shape memory elementshaving first and second opposite ends, wherein the first end of eachouter shape memory element is connected to the first outer rim portionand the second end of each outer shape memory element is connected tothe second outer rim portion, wherein the outer main body portionincludes a first outer side wall portion, a second outer side wallportion, and an outer contact portion extending transversely between thefirst and second outer side wall portions, and at least a first bumpstop assembly that includes a first inner rim portion, a second innerrim portion and an inner main body portion, wherein the inner main bodyportion includes a plurality of inner shape memory elements having firstand second opposite ends, wherein the first end of each inner shapememory element is connected to the first inner rim portion and thesecond end of each inner shape memory element is connected to the secondinner rim portion, wherein the inner main body portion includes a firstinner side wall portion, a second inner side wall portion and an innercontact portion extending transversely between the first and secondinner side wall portions, and wherein the inner contact portion iscoupled to the outer contact portion.
 2. The wheel assembly of claim 1further comprising a tread portion, wherein the tread portion includes aplurality of tread shape memory elements, wherein the tread portioncouples the inner contact portion to the outer contact portion.
 3. Thewheel assembly of claim 2 wherein the plurality of tread shape memoryelements comprises first and second tread shape memory elements, whereinthe plurality of outer shape memory elements comprises first and secondouter shape memory elements, wherein the plurality of inner shape memoryelements comprises first and second inner shape memory elements, andwherein the first tread shape memory element couples the first outershape memory element to the first inner shape memory element.
 4. Thewheel assembly of claim 2 wherein the first tread shape memory elementwraps around the first outer shape memory element and the first innershape memory element, thereby coupling the first outer shape memoryelement to the first inner shape memory element.
 5. The wheel assemblyof claim 2 wherein the first tread shape memory element includes aplurality of coils and defines a spring interior, and wherein the firstouter shape memory element and the first inner shape memory elementextend through the spring interior, thereby coupling the first outershape memory element to the first inner shape memory element.
 6. Thewheel assembly of claim 5 wherein the second tread shape memory elementincludes a plurality of coils, wherein at least one of the plurality ofcoils of the first tread shape memory element is connected to at leastone of the plurality of coils of the second tread shape memory element.7. The wheel assembly of claim 1 wherein the plurality of outer crossmembers define a stop surface, wherein the first and second inner rimportions define an inner contact surface, wherein a deflection distanceis defined between the inner contact surface and the stop surface,wherein when the outer main body portion is deflected a predetermineddistance the inner contact surface contacts the stop surface.
 8. Thewheel assembly of claim 1 wherein the plurality of outer shape memoryelements comprises a first set of lug shape memory elements and a secondset of non-lug shape memory elements, wherein the lug shape memoryelements have a greater stiffness than the non-lug shape memoryelements.
 9. The wheel assembly of claim 1 further comprising a secondbump stop assembly that includes a second inner contact portion, andwherein the second inner contact portion is coupled to the outer contactportion.
 10. The wheel assembly of claim 1 wherein the plurality ofouter shape memory elements and plurality of inner shape memory elementsare made of a shape memory alloy.
 11. A wheel assembly comprising: anouter rim assembly that includes a first outer rim portion, a secondouter rim portion, and a plurality of outer cross members extendingbetween the first outer rim portion and the second outer rim portion, atire assembly connected to the outer rim assembly, wherein the tireassembly includes an outer main body portion, wherein the outer mainbody portion includes a first outer side wall portion, a second outerside wall portion, and an outer contact portion extending transverselybetween the first and second outer side wall portions, and at least afirst bump stop assembly that includes a first inner rim portion, asecond inner rim portion and an inner main body portion, wherein theinner main body portion includes a first inner side wall portion, asecond inner side wall portion and an inner contact portion extendingtransversely between the first and second inner side wall portions, andwherein the inner contact portion is coupled to the outer contactportion.
 12. The wheel assembly of claim 11 wherein the tire assemblydefines a tire assembly outer diameter, and wherein the inner contactportion is coupled to the outer contact portion about the tire assemblyouter diameter.
 13. The wheel assembly of claim 11 wherein the pluralityof outer cross members define a stop surface, wherein the first andsecond inner rim portions define an inner contact surface, wherein adeflection distance is defined between the inner contact surface and thestop surface, wherein when the outer main body portion is deflected apredetermined distance the inner contact surface contacts the stopsurface.
 14. The wheel assembly of claim 11 wherein the outer main bodyportion includes at least a first outer shape memory element havingfirst and second opposite ends, wherein the first end of the first outershape memory element is connected to the first outer rim portion and thesecond end of the first outer shape memory element is connected to thesecond outer rim portion, wherein the inner main body portion includesat least a first inner shape memory element having first and secondopposite ends, wherein the first end of the first inner shape memoryelement is connected to the first inner rim portion and the second endof the first inner shape memory element is connected to the second innerrim portion, and wherein the first inner shape memory element is coupleto the first outer shape memory element.
 15. The wheel assembly of claim14 further comprising at least a first tread shape memory element,wherein the first tread shape memory element couples the first innershape memory element to the first outer shape memory element.